Lapping

Minimal roughness and mirror finishes on metal, ceramic and glass, with the right abrasives.

Lapping is a mechanical operation carried out on metal, ceramic or glass surfaces to reduce roughness to a minimum; with suitable abrasives, surfaces can be brought to a mirror finish.

In precision engineering, lapping is applied to steels after hardening, above all in making moulds for plastics, so that the moulded parts come out glossy and clear. The steel mould surface is finished with very fine abrasive papers or emery (diamond powder, silicon carbide and so on).

Lapping plastic moulds is demanding work, usually done by hand: it starts with coarse abrasive paper after the die or punch has been machined (milling, EDM and so on) and moves to progressively finer grits. Lapping is also used in jewellery, by hand or with rotating felt brushes depending on the piece.